Pressure reducing valve



March 26, 1935. s. E. B. SODERBERG PRESSURE REDUCING VALVE Filed Nov. 2a, 1953 INVENTOR ffien Q file/fie B Z a AT fdRNEY Patented Mar. 26, 1935 1 995,32

UNITED STATES PATENT rms PRESSURE REDUCING VALVE Ste-n E. B. Soderberg, Passaic, N. 1., assignor to Leslie Bompany; Lyndhurst, N. J.

Application November 28, 1933, Serial No. 700,064; 3 Claims. (Cl. 236'80) The present invention relates to devices for The arrangement described and claimed in the governing the admission of heating fluid to a said co-pending application results in a constant heating device in installations where liquids or reduced pressure in the coil 2 for any given temfluids are to be heated to a constant temperature. perature of the water irrespective of the pressure A. typical installation of this sort is represented of the steam delivered to the pressure reducing by the case of a drum holding water which is to valve. This is a great advance over prior devices be heated to a constant temperature for use for but it has been found in practice that for the any desired purpose, the heating being done by salreof'safety it is advisable to add a further presmeans of steam and, in the form used herein for sure reducing valve to the system. The coil and w illustrative purposes, by means of a coil arranged the drum 1 are calculated for such pressures as inside of the drum. are actually to be used and these pressures will A pressure reducing valve for use in such an usually be much lower than the pressure of the installation is described and claimed in combisteam suppli to the Valve Thus, the Steam nation with other elements in my co-pending delivered to the valve 3 by pip 4 may Come fIOm 5 application, Serial Number 625,309. The present boiler generating Steam for power p p invention relates to similar installations but prod ay b p qm While in the vides a further desirable feature in the pressure C011 2 the maximum Steam p u d e reducing valve. heating purposes may be something like 5# per The invention is illustratedjn the accompanysq. in. This involves the danger that, the valve 30 ing drawing, in which Fig. 1 shows a water drum, being Controlled in IeSDQnSG t0 the temp at re o portions of which are broken away, heated by the water only, it will under some conditions admeans of a steam coil supplied with steam from full p su steam to the Coil 2. For this a, high pressure sourc the flow w th 11 being reason it has in practice proved advisable to incontrolled by a thermostatically controlled presm a further pressure reducing Valve, P

5 sure reducing valve in accordance with the presably a a O th pressure educ n valve 3, to out invention, and Fig. 2 shows the pressure red e the p su d w to a p t s ht y a v ducing valve in central longitudinal section. the maximum d s r d in Coil The cost of this The drum containing the water to be heated is 59601101 Pressure reducing Valve is an ject OIl Shown t 1, th 11 b means of h h t water and the present invention is intended to provide :0 is to be heated appearing at 2 and the pressure thissafety feature without the use of such ad- 36 reducing valve being shown at 3, Th source of ditional pressure reducing valve. This is done high pressure steam is not illustrated, but such by modifying the Valv 3 rom the form shown in steam is supplied from such source to the pres- Said farmer p o sure reducing valve by means of the pipe 4, the The Parts of ihe Valve below phr m 8 g5 steam h e pressure h b reduced being remain as. before, the modification being introveyed t th 11 2 from th valve 3 y means duced in the mechanism above this diaphragm.

f th pipe 5, ,11; i d i t keep t t The valve controlling the flow of steam from perature of the water in drum 1 at as nearly cone pipe 4 to the p p 5 is Shown at A light stant a temperature as feasible. A thermostatic pring 10 urges i w r its Seat and p ure l t t dj t th body of water isshown above the piston 11 tends to open it further.

at 6. The action of this element and the assos Pressure is admitted t0 the Space above D S- I ciated parts results in a variable pressure at pipe 7. i 11 from'the annular Space 12 a ound the stem This is fully described in the co-pending applicaof pilot Valve 16 y means Of the duct 13. The

tion referred toabove and will not be repeated Space on the we Si Of Piston 11 is in 1 1 here as it forms no part of the present invention. Communication With P 5 by means of pen- The pressure in pipe lfalls withan in i th ings 1414 and the pressure on the lower side temperature. This is the result of the specific isadded to the force of the spring 10 to oppose thermostatic apparatus employed. As wi11 b unthe pressure on the upper side. Pressure medium derstood from a reading of the following descripfrom pipe 4 is admitted to the annular Space 1 ;0 tion of the apparatus and its action, a thermovthrough'the d t 1 i i sion being. constatic arrangement could be employed in which trolled by the pilot valve 16. This pilot valve is the pressure rises with the temperature. Such urged towards its seat by the spring 17 and is an element is also shown in the prior applicaforced off its seat by the diaphragm 8 pressing on tion, and the modification of the present device the upperend of the stem 19. Steam leaking past required for such a case will be obvious. the stem Iii-escapes by way of duct 33 to the lowi pressure pipe 5. All of this is of the usual construction.

The diaphragm 8 is clamped into place by the housin 20, which terminates at its upper end in a flange 21 against which is clamped a diaphragm 22 with a diaphragm chamber 23 on its upper side.

Pressure from pipe 7, varying with the temperature of the water in the tank to be heated as described above, is admitted into the diaphragm chamber 23.

Extending between the two diaphragm 8 and 22 is a structure for transmitting movement which will be described next.

At the upper end of this structure is the circular disk 30 which is clamped against diaphragm 22 by means of its threaded stem 46 extending through a central opening in the diaphragm and nut 35 screwed on this stem. The lower side of disk 30 has a cylindrical central projection fitting snugly into the upper end of the cylindrical box 40, whose lower end has a short stem 24 screwed into the upper end of hollow stem 29. Within the hollow stem 29 there is a plug 2'7 into which extends the stem 26 of foot 25, which bears against diaphragm 8. Plug 27 is urged downward toward the bottom of hollow stem 29 by spring 41, whose upper end abuts against a plug 42. The upper side of this plug 42.bears against the lower end of adjusting screw 43 which is threaded through the bottom of box 40 and which is provded with a lock-nut 28. Lock-nut 28 and the head 45 of adjusting screw 43 are accessible through lateral openings 31 in box 40. The compression of spring 41 can thus be adjusted.

Box 40 is pressed upward by spring 44 whose lower end abuts against shoulder 32 in housing 20.

The lower end of hollow stem 29 will upon ,sufllcient downward movement abut against shoulder 48 of housing 20, as described below.

Stem 46 and nut 35 form a stop to abut against spaced stops 36 thereby to limit the upward movement of diaphragm 22.

For a given temperature of the water in drum 1 there will be delivered into the diaphragm chamber 23 fluid at acertain corresponding pressure. Any downward movement of diaphragm 22 will be transmitted to diaphragm 8 by the movement-transmitting structure described above, beginning with disk 30 and ending with foot 25. Diaphragm 8 will in turn transmit it to pilot valve 12 and will open this pilot valve against the pressure of spring 17. Spring 41 keeps plug 27 against its stop at the bottom of the hollow interior oi stem 24 during such operation. As a result a definite amount of steam will be delivered through duct 13 to the chamber above the piston 11. The leakage from this chamber past the piston ll will result in a definite pressure above the piston and this in turn will tend to give indefinite position to the valve 9 and hence a definite pressure in pipe and coil 2. The pressure in chamber 23 is however not the only factor determining the position of valve 9. The rate at which the steam in the coil is condensed at once and directly affects the pressure in the coil and therefore on the under side of diaphragm 8 and on the lower side of piston 11. This will result in the usual way in a change in the position of valve 9. Thus, if water is taken from tank 1 at an increased rate, the drop in temperature will cause a rise in the pressure in chamber 23 and at the same time the more rapid condensation in coil 2 will result in a drop of the pressure in the coil and on the lower side of piston 11 and diaphragm 8. Pilot valve 16 will open further and admit more steam to the chamber above the piston 11 thereby opening valve 9 farther. The net result is that a definite pressure in pipe 5 and coils 2 will be maintained responsive to the temperature of the water in tank 1.

As the pressure in chamber 23 falls, spring 44 forces the diaphragm 22 upward, and in order to prevent injury to the diaphragm its upward motion is-limited by the stem 34 and nut 35 which come into contact with the stops 36 when the permissible amount of upward motion has occurred. The stiflness of the spring and size of the diaphragm are such that this will occur when the pressure in chamber 23 is about atmospheric.

Upward pressure on the lower side of diaphragm 8 will tend to compress spring 41, the position of diaphragm 22 being substantially uninfluenced. This constitutes a safety feature, pressure above a selected point in pipe 5 being prevented. Such excessive pressure closes pilot valve 16 and this shuts oil valve 9. In general, an increase of pressure in coil 2 results in a throttling of the pilot valve and a resultant closing movement of valve 9. Spring 41 is so selected and its compression so adjusted by means of screw 43 that when stem 29 engages shoulder 48 in housing 20, the spring is compressed just suificiently to balance the upward force of the desired maximum reduced pressure acting on diaphragm 8. Any increase in this pressure will compress spring 41 at'once and throttle the pilot valve and main valve 9.

The theory and action of the device may be further elucidated as follows:

In normal operation, spring 41 holds plug 27 against the bottom of hollow stem 29 and the impulse-transmitting structure beginning with disk 30 and ending with foot 25 acts as one rigid piece. The action 01' the device is then the same as in the prior device described more fully in my former application. It now a sudden drop in the temperature of the liquidin container 1 occurs from any cause, the pressure in chamber 23 will rise and in addition the pressure in coils 2 will drop because of accelerated condensation of the heating medium. If both of these are allowed to act to their full extent, the valve 9 will open wide and allow the pressure in coils 2 to exceed the safe limit. To avoid this, the distance to which diaphragm 22 is permitted to force down hollow stem 29 is limited by having the end of the stem abut against the annular shoulder 48. As long as this condition remains, the'movement of the lower diaphragm is dependent only on the pressure on its lower side and the opposing pressure of spring 41, and the apparatus works like the usual single-diaphragm reduction valve. The pressure in coils 2 is then limited to some desired low pressure, its exact amount being regulable by setting of set-screw 43. There is therefore no danger of excessive pressures in the coils.

It will be noted upon analyzing this matter, that for this action the following features are required: (a) an element (30) abutting against diaphragm 22; (b) an element (25) (which may be unitary with plug 27) abutting against diaphragm 8; (c) a compression spring (41) forcing these two elements apart; (d) means to limit the distance to which the spring can force them apart (this limit being furnished by the bottom of hollow stem 29 being engaged by plug 27) and (e) a stop for the downward movement of the eleplicetion, "but as the pressure in the heating coils approaches the upper limit of safety, the present modification results in e tlu'ottlins action of the valve, regardless of the temperature 0! the water; and when the limit is reached it shuts oil the steam completely.

It will be obvious that instead of heating coils being used, the steam might be injected directly into the water. The action of the apparatus would he just es described. some other changes will no doubt be possible in practicing my inventime without a. departure irorn its spirit.

Whet I claim is:

1. In apparatus of the class described in which steam to heat water in a container is led through a, reducing valve, said reducing valve havhig a. moth control valve whose position is governed by the position of a. pilot valve and a pair of die.- phragmsthe position of one of which determines the position of the pilot valve, the position of said first diaphragm being generally influenced by the position of the second diaphragm and the posilimiting the distance to which they can be forced sport, and a stop limiting the motion of the element engaging the second diaphragm in the di rectlon toward the first diaphragm.

2. Apparatus according to claim 1, the two diaphragm being parallel and opposite each other, the two elements engaging the diaphragm on the sides facing each other, the first stop being provided by e part of one of the elements en gaging a. part of the other element, and the second stop being provided by e. fixed abutment en= caged by the second element. 3. In apparatus of the class described in which a steam to heel; waterin a container is led through main control valve whose position is governed by the positionof a. pilot valve and a pair of per allel horizontal diophragms facing each other the position of one of wmch determines the posi tion of the pilot valve, the position of the mist diaphragm being generally influenced by the m sitlon of the second diaphragm, and the position oi the second diaphragm being responsive to the temperature of the water approaching the second diaphragm more as the temperature falls; the combination oil an element engaging the lower side of the upper diaphragm and having a hollow stem, on element engaging the upper side of the lower diaphragm and comprising a portion reciprocable in said hollow stem, 9, spring, engaging said portion and'said first named element so as to resiliently force them each toward its associated diaphragm, the hollow stem having a stop limiting the extent of saidn lotion, anda stop fixed a reducing, valve, said reducing valve having at 

